breaking news at the marine base in quantico overnight. A marine killing two other marines as well as himself in a shooting. Abc's reena ninan has the latest on this story. Good morning, reena. Reporter: Elizabeth, good morning to you. Authorities are trying to learn more about the suspect and the motive and why three marines are dead. One of them, a woman. Big breaking news this morning, a shooting on the marine corps base on quantico. Three people are dead. Reporter: The shooting began around 11:00 p.M. Last night. The suspect shot and killed one marine before barricading himself inside a barracks building near the officer candidates school at quantico marine corps base. MPs RESPONDED TO THE SCENE Surround the suspect and putting the base on lockdown. Announcements were made over the basewide p.A. System and notifications sent to residents via facebook and twitter. Base residents are to follow all instructions being delivered by the giant voice system. Please remain inside your homes with doors locked. Suspect barricaded by law enforcement personnel, not under custody. The standoff lasted throughout the night before the all-clear was given basewide. According to sources, the suspect died from a self-inflicted gunshot wound before taking the life of one other marine who was trapped in the barracks with him. Officials believe this was an isolated incident but to give you a sense of what a tough week it's been for the marine corps, there were no fatalities in the entire month in afghanistan, but just in the u.S. This week alone, there were ten deaths in the marines.

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